1. Field of the Invention
The present invention relates to an electronic equipment control system that is mounted in a vehicle.
2. Description of the Related Art
The number of various kinds of electronic devices that are mounted in a vehicle to provide various kinds of functions has increased year by year. In order to effectively utilize the functions, it has been required interface structures. In order to meet demand for inexpensive devices having high performance, system sharing among various vehicles and coordination among various systems have been adopted. For example, JP-A-2006-142994 discloses a hierarchical system architecture, in which various kinds of system hardware and software are formed into an application layer that includes coordinating control logic or the like by stacking hardware physical layer on which front-end devices are disposed and a system-infrastructure-layer that masks the hardware structure.
In the above hierarchical system architecture the following operations are carried out: the input data from the hardware physical layer is delivered one after the other from lower layers to higher layers; a process of reducing the data into control output data for the hardware physical layer is carried out in the application layer, and the result of the processes that are carried out in the application layer is delivered one after the other from the higher layers to the lower layers; and finally, driving data are delivered from the hardware physical layer. The input data of one layer are processed in the same layer before delivering to the next higher layer to be processed. Then, the data processed in the higher layer is delivered to the lower layer as a process result. That is, the input and output data that are exchanged between a lower layer and higher layers are closely related to the input and out data of the higher layers. In other words, the control data are not confined in each layer. As a result, if some coordination related trouble occurs in one of the layers, such trouble may spread over the higher and lower layers of the above hierarchical system architecture and various portions of each layer thereof.